Tetralogy of Fallot

CASE REPORT

TETRALOGY OF FALLOT

Presenter : Ardyansyah Nasution

Supervisor : dr. H. Muhammad Ali, Sp.A (K)

DEPARTEMEN OF PEDIATRICS

FAKULTAS KEDOKTERAN

UNIVERSITAS SUMATERA UTARA

2010

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CASE REPORT

TETRALOGY OF FALLOT

Presenter : Ardyansyah Nasution

Day/Date : Tuesday/Mar 9th 2010

Supervisor : dr. H. Muhammad Ali,

Sp.A (K)

Introduction

Tetralogy of Fallot (ToF) is one of the most common congenital heart disorders

(CHDs). ToF is a relatively uncommon but serious combination of defects that are

the result of abnormal development in the embryo during the formation of the

heart and great blood vessels. ToF is classified as a cyanotic heart disorder

because the condition results in an inadequate flow of oxygenated blood to the

systemic circulation. The condition causes mixing of oxygen-poor blood with the

oxygen-rich blood being pumped out of the heart and into the circulatory system

of blood vessels.

The blood leaving the heart has less oxygen than is needed by the organs

and tissues of the body, a condition called hypoxemia.

Chronic (ongoing, long-term) lack of oxygen causes cyanosis, a bluish

color of the skin, lips, and membranes inside the mouth and nose.

Patients with ToF initially present with cyanosis shortly after birth, thereby

attracting early medical attention.1

2

http://www.emedicinehealth.com/script/main/art.asp?articlekey=2738







Louis Arthur Fallot, after whom the name tetralogy of Fallot is derived, was not

the first person to recognize the condition. Niels Stensen first described ToF in

1672; however, it was Fallot who first accurately described the clinical and

complete pathologic features of the defects.1

Although the disorder was clinically diagnosed much earlier, no treatment was

available until the 1940s. Cardiologist Helen Taussig recognized that cyanosis

progressed and inevitably led to death in infants with ToF. She postulated that the

cyanosis was due to inadequate pulmonary blood flow. Her collaboration with

Alfred Blalock led to the first type of palliation for these infants. In 1944, Blalock

operated on an infant with ToF and created the first Blalock-Taussig shunt

between the subclavian artery and the pulmonary artery.1

This pioneering surgical technique opened a new era in neonatal cardiac surgery.

This was followed by development of the Potts shunt (from the descending aorta

to the left pulmonary artery), the Glenn shunt (from the superior vena cava to the

right pulmonary artery), and the Waterston shunt (from the ascending aorta to the

right pulmonary artery).1

Scott performed the first open correction in 1954. Less than half a year later,

Lillehei performed the first successful open repair for ToF using controlled cross

circulation, with another patient serving as oxygenator and blood reservoir. The

following year, with the advent of CPB by Gibbons, another historic era of

cardiac surgery was established. Since then, numerous advances in surgical

technique and myocardial preservation have evolved in the treatment of ToF.1

ToF is the most common cyanotic heart defect seen in children beyond infancy.

ToF occurs in 3-6 infants for every 10,000 births and is the most common cause

of cyanotic CHD (10% of all CHD). The disorder is observed in other mammals,

including horses and rats. ToF accounts for a third of all CHD in patients younger

than 15 years. In most cases, ToF is sporadic and nonfamilial. The incidence in

siblings of affected parents is 1-5%, and it occurs more commonly in males than

in females. The disorder is associated with extracardiac anomalies such as cleft lip

and palate, hypospadias, and skeletal and craniofacial abnormalities.1, 2

3

The causes of ToF are unknown, although genetic studies suggest a multifactorial

etiology. Based on studies with affected Keeshunds, the mode of inheritance is

believed to be autosomal recessive with variable expression. Prenatal factors

associated with a higher incidence of ToF include maternal rubella (or other viral

illnesses) during pregnancy, poor prenatal nutrition, maternal alcohol use, taking

medications to control seizures during pregnancy, Having a condition called

phenylketonuria, maternal age older than 40 years, and diabetes. Children with

Down syndrome have a higher incidence of ToF.1, 3

As the name implies, ToF consists of 4 defects. These are pulmonic stenosis,

ventricular septal defect (VSD), over riding aorta and right ventricular

hypertrophy secondary to the pulmonic stenosis. Occasionally, a few children also

have an atrial septal defect, which makes up the pentad of Fallot. The basic

pathology of tetralogy is due to the underdevelopment of the right ventricular

infundibulum, which results in an anterior-leftward malalignment of the

infundibular septum. This malalignment determines the degree of right ventricular

outflow tract obstruction. Evidence suggests that these defects are the result of

varying degrees of abnormality in a single developmental process - the growth

and fusion of the conotruncal septum. It is possible that pulmonic stenosis or a

ventricular septal defect, both of which occur independently, may be less severe

manifestations of the same genetic defect. 1

In pulmonic stenosis, there is partial obstruction of blood flow from the right side

of the heart through the pulmonic valve. Because of the obstruction, the right side

of the heart has to work harder to pump blood to the lungs. This causes an

increase in the mass of the heart muscle, or right ventricular hypertrophy, one of

the hallmarks of this disorder. Obstruction to pulmonary arterial blood flow is

usually at both the right ventricular infundibulum (subpulmonic area) and the

pulmonary valve. The main pulmonary artery is often small, and various degrees

of branch pulmonary artery stenosis may be present. Complete obstruction of right

ventricular outflow (pulmonary atresia with VSD) is classified as an extreme form

of tetralogy of Fallot.4

4

http://emedicine.medscape.com/article/943216-overview

http://www.daviddarling.info/encyclopedia/P/phenylketonuria.html

http://www.upei.ca/~cidd/howare.htm#ar

A ventricular septal defect is a defect or hole in the muscular wall of the heart (the

septum) that separates the right and left ventricles. The aorta which carries blood

from the left side of the heart, is mal-positioned to varying degrees with ToF.

Normally, the blood that is pumped to the body from the left side of the heart is

fully saturated with oxygen. The oxygen is extracted from the blood for use in the

various tissues and then the deoxygenated blood is returned to the right side of the

heart. It goes to the lungs to pick up oxygen, and then is delivered back to the left

side of the heart, from which it is pumped out to the tissues again. The result of

the defects that make up the ToF is that poorly oxygenated blood is delivered to

the body. This causes general cyanosis or a grey tone to tissues that would

normally be pink.4

The pulmonary valve annulus may be of nearly normal size or quite small. The

valve itself is often bicuspid and, occasionally, is the only site of stenosis. More

commonly, the subpulmonic muscle, the crista supraventricularis, is hypertrophic,

which contributes to the infundibular stenosis and results in an infundibular

chamber of variable size and contour. When the right ventricular outflow tract is

completely obstructed (pulmonary atresia), the anatomy of the branch pulmonary

arteries is extremely variable; a main pulmonary artery segment may be in

continuity with right ventricular outflow, separated by a fibrous but imperforate

pulmonary valve, or the entire main pulmonary artery segment may be absent.

Occasionally, the branch pulmonary arteries may be discontinuous. In these more

severe cases, pulmonary blood flow may be supplied by a patent ductus arteriosus

(PDA) and by major aortopulmonary collateral arteries (MAPCAs) arising from

the aorta.4

The VSD is usually nonrestrictive and large, is located just below the aortic valve,

and is related to the posterior and right aortic cusps. Rarely, the VSD may be in

the inlet portion of the ventricular septum (atrioventricular septal defect). The

normal fibrous continuity of the mitral and aortic valves is usually maintained.

The aortic arch is right sided in 20%, and the aortic root is usually large and

overrides the VSD to a varying degree. When the aorta overrides the VSD more

than 50% and if muscle is significantly separating the aortic valve and the mitral

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annulus (subaortic conus), this defect is usually classified as a form of double-

outlet right ventricle; the pathophysiology is the same as that for tetralogy of

Fallot.4

Systemic venous return to the right atrium and right ventricle is normal. When the

right ventricle contracts in the presence of marked pulmonary stenosis, blood is

shunted across the VSD into the aorta. Persistent arterial desaturation and

cyanosis result. Pulmonary blood flow, when severely restricted by the

obstruction to right ventricular outflow, may be supplemented by the bronchial

collateral circulation (MAPCAs) and, in the newborn, by a PDA. Peak systolic

and diastolic pressures in each ventricle are similar and at the systemic level. A

large pressure gradient occurs across the obstructed right ventricular outflow tract,

and pulmonary arterial pressure is normal or lower than normal. The degree of

right ventricular outflow obstruction determines the timing of the onset of

symptoms, the severity of cyanosis, and the degree of right ventricular

hypertrophy. When obstruction to right ventricular outflow is mild to moderate

and a balanced shunt is present across the VSD, the patient may not be visibly

cyanotic (acyanotic or “pink” tetralogy of Fallot).4

The clinical features are directly related to the severity of the anatomic defects.

Most infants with ToF have difficulty with feeding, and failure to thrive is

commonly observed. Puberty may also be delayed in patients who do not undergo

surgery. Infants with pulmonary atresia may become profoundly cyanotic as the

ductus arteriosus closes unless bronchopulmonary collaterals are present.

Occasionally, some children have just enough pulmonary blood flow and do not

appear cyanotic; these individuals remain asymptomatic until they outgrow their

pulmonary blood supply.4

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Systolic pressures in the RV, LV, and AO are identical. Level of arterial desaturation is related to severity of

the RV outflow tract obstruction. Atrial pressures are mean pressures. AO = aorta; IVC = inferior vena cava;

LA = left atrium; LV = left ventricle; PA = pulmonary artery; PV = pulmonary veins; RA = right atrium; RV

= right ventricle; SVC = superior vena cava.

Infants with mild degrees of right ventricular outflow obstruction may initially be

seen with heart failure caused by a ventricular-level left-to-right shunt. Often,

cyanosis is not present at birth, but with increasing hypertrophy of the right

ventricular infundibulum and patient growth, cyanosis occurs later in the 1st year

of life. It is most prominent in the mucous membranes of the lips and mouth and

in the fingernails and toenails. In infants with severe degrees of right ventricular

outflow obstruction, neonatal cyanosis is noted immediately. In these infants,

pulmonary blood flow may be dependent on flow through the ductus arteriosus.

When the ductus begins to close in the 1st few hours or days of life, severe

cyanosis and circulatory collapse may occur. Older children with long-standing

cyanosis who have not undergone surgery may have dusky blue skin, gray sclerae

with engorged blood vessels, and marked clubbing of the fingers and toes.4

Dyspnea occurs on exertion. Infants and toddlers play actively for a short time and

then sit or lie down. Older children may be able to walk a block or so before

stopping to rest. Characteristically, children assume a squatting position for the

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relief of dyspnea caused by physical effort; the child is usually able to resume

physical activity within a few minutes. These findings occur most often in patients

with significant cyanosis at rest.4

Paroxysmal hypercyanotic attacks (hypoxic, “blue,” or “tet” spells) are a

particular problem during the 1st 2 year of life. Hypoxic spell of ToF requires

immediate recognition and appropriate treatment, because it can lead to serious

complications of the central nervous system. Hypoxic spells are characterized by a

paroxysm of hyperpnea (i.e., rapid and deep respiration) and restless, irritability

and prolonged crying, increasing cyanosis, decreasing intensity of the heart

murmur, gasping respirations ensue, and syncope may follow. Hypoxic spells

occur in infants, with a peak incidence between 2 and 4 months of age. These

spells usually occur in the morning after crying, feeding, or defecation. The spells

may last from a few minutes to a few hours but are rarely fatal. Short episodes are

followed by generalized weakness and sleep. Severe spells may progress to

unconsciousness and, occasionally, to convulsions, limpness, hemiparesis,

cerebrovascular accident, or even death. The onset is usually spontaneous and

unpredictable. Spells are associated with reduction of an already compromised

pulmonary blood flow, which when prolonged results in severe systemic hypoxia

and metabolic acidosis. Infants who are only mildly cyanotic at rest are often

more prone to the development of hypoxic spells because they have not acquired

the homeostatic mechanisms to tolerate rapid lowering of arterial oxygen

saturation, such as polycythemia.2, 4

Depending on the frequency and severity of hypercyanotic attacks, one or more of

the following procedures should be instituted in sequence: (1) placement of the

infant on the abdomen in the knee-chest position while making certain that the

infant's clothing is not constrictive, (2) administration of oxygen (although

increasing inspired oxygen will not reverse cyanosis caused by intracardiac

shunting), and (3) injection of morphine subcutaneously in a dose not in excess of

0.2 mg/kg. Calming and holding the infant in a knee-chest position may abort

progression of an early spell. Premature attempts to obtain blood samples may

cause further agitation and be counterproductive.4

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Because metabolic acidosis develops when arterial PO2 is less than 40 mm Hg,

rapid correction (within several minutes) with intravenous administration of

sodium bicarbonate is necessary if the spell is unusually severe and the child

shows a lack of response to the foregoing therapy. Recovery from the spell is

usually rapid once the pH has returned to normal. Repeated blood pH

measurements may be necessary because rapid recurrence of acidosis may ensue.

For spells that are resistant to this therapy, drugs that increase systemic vascular

resistance, such as intravenous methoxamine or phenylephrine, improve right

ventricular outflow, decrease the right-to-left shunt, and thus improve the

symptoms. β-Adrenergic blockade by the intravenous administration of

propranolol (0.1 mg/kg given slowly to a maximum of 0.2 mg/kg) is also useful.4

The pulse is usually normal, as is venous and arterial pressure. The left anterior

hemithorax may bulge anteriorly because of right ventricular hypertrophy. The

heart is generally normal in size, and a substernal right ventricular impulse can be

detected. In about half the cases, a systolic thrill is felt along the left sternal border

in the 3rd and 4th parasternal spaces. The systolic murmur is usually loud and

harsh; it may be transmitted widely, especially to the lungs, but is most intense at

the left sternal border. The murmur is generally ejection in quality at the upper

sternal border, but it may sound more holosystolic toward the lower sternal

border. It may be preceded by a click. The murmur is caused by turbulence

through the right ventricular outflow tract. It tends to become louder, longer, and

harsher as the severity of pulmonary stenosis increases from mild to moderate;

however, it can actually become less prominent with severe obstruction,

especially during a hypercyanotic spell. Either the 2nd heart sound is single, or the

pulmonic component is soft. Infrequently, a continuous murmur may be audible,

especially if prominent collaterals are present.4

Hemoglobin and hematocrit values are usually elevated in proportion to the

degree of cyanosis. The oxygen saturation in the systemic arterial blood typically

varies from 65-70%. All patients with ToF who experience significant cyanosis

have a tendency to bleed because of decreased clotting factors and low platelet

count. The usual findings are diminished coagulation factors. The total fibrinogen

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levels are also diminished and are associated with prolonged prothrombin and

coagulation times.1

The electrocardiogram demonstrates right axis deviation (RAD) (+120 to +150

degrees) in cyanotic ToF. In the acyanotic form, the QRS axis is normal. and

evidence of RVH hypertrophy. RVH is usually present, but the strain pattern is

unusual. CVH may be seen in the acyanotic form. RAH is occasionally present. A

dominant R wave appears in the right precordial chest leads (Rs, R, qR, qRs) or an

RSR¢ pattern. In some cases, the only sign of right ventricular hypertrophy may

initially be a positive T wave in leads V3R and V1. The P wave is tall and peaked

or sometimes bifid.1, 4

Roentgenographically, The typical configuration as seen in the anteroposterior

view consists of a narrow base, concavity of the left heart border in the area

usually occupied by the pulmonary artery, and normal heart size. The hilar areas

and lung fields are relatively clear because of diminished pulmonary blood flow

or the small size of the pulmonary arteries, or both.. “Black” lung fields are seen

in ToF with pulmonary atresia.2, 4

The hypertrophied right ventricle causes the rounded apical shadow to be up-tilted

so that it is situated higher above the diaphragm than normal. The cardiac

silhouette has been likened to that of a boot or wooden shoe (coeur en sabot).

Right atrial enlargement (25%) and right aortic arch (25%) may be present, which

results in an indentation of the leftward-positioned air-filled tracheobronchial

shadow in the anteroposterior view.2, 4

X-ray findings of acyanotic ToF are indistinguishable from those of a small to

moderate VSD, but patients with ToF have RVH rather than LVH on the ECG.2

Two-dimensional echo and Doppler studies can make the diagnosis and quantitate

the severity of ToF. Two-dimensional echocardiography provides information

about the extent of aortic override of the septum, the location and degree of the

right ventricular outflow tract obstruction, the size of the proximal branch

pulmonary arteries, and the side of the aortic arch. The echocardiogram is also

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useful in determining whether a PDA is supplying a portion of the pulmonary

blood flow. It may obviate the need for catheterization.4

Cardiac catheterization demonstrates a systolic pressure in the right ventricle

equal to systemic pressure. If the pulmonary artery is entered, the pressure is

markedly decreased, although crossing the right ventricular outflow tract,

especially in severe cases, may precipitate a tet spell. Pulmonary arterial pressure

is usually lower than normal, in the range of 5–10 mm Hg. The level of arterial

oxygen saturation depends on the magnitude of the right-to-left shunt; in “pink

tets,” systemic saturation may be normal, whereas in a moderately cyanotic

patient at rest, it is usually 75–85%.4

Selective right ventriculography best demonstrates the anatomy of the tetralogy of

Fallot. Contrast medium outlines the heavily trabeculated right ventricle. The

infundibular stenosis varies in length, width, contour, and distensibility. The

pulmonary valve is usually thickened, and the annulus may be small. In patients

with pulmonary atresia and VSD, the anatomy of the pulmonary vessels may be

extremely complex, for example, discontinuity between the right and left

pulmonary arteries. Complete and accurate information regarding the anatomy of

the pulmonary arteries is important when evaluating these children as surgical

candidates.4

Left ventriculography demonstrates the size of the left ventricle, the position of

the VSD, and the overriding aorta; it also confirms mitral-aortic continuity,

thereby ruling out a double-outlet right ventricle. Aortography or coronary

arteriography outlines the course of the coronary arteries. In 5–10% of patients

with the ToF, an aberrant major coronary artery crosses over the right ventricular

outflow tract; this artery must not be cut during surgical repair. Verification of

normal coronary arteries is important when considering surgery in young infants

who may need a patch across the pulmonary valve annulus. Echocardiography

may delineate the coronary artery anatomy; angiography is reserved for cases in

which questions remain.4

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Treatment of the ToF depends on the severity of the right ventricular outflow tract

obstruction. Infants with severe ToF require medical treatment and surgical

intervention in the neonatal period. Therapy is aimed at providing an immediate

increase in pulmonary blood flow to prevent the sequelae of severe hypoxia. The

infant should be transported to a medical center adequately equipped to evaluate

and treat neonates with congenital heart disease under optimal conditions. It is

critical that oxygenation and normal body temperature be maintained during the

transfer. Prolonged, severe hypoxia may lead to shock, respiratory failure, and

intractable acidosis and will significantly reduce the chance of survival, even

when surgically amenable lesions are present. Cold increases oxygen

consumption, which places additional stress on a cyanotic infant, whose oxygen

delivery is already limited. Blood glucose levels should be monitored because

hypoglycemia is more likely to develop in infants with cyanotic heart disease.4

Infants with marked right ventricular outflow tract obstruction may deteriorate

rapidly because as the ductus arteriosus begins to close, pulmonary blood flow is

further compromised. The intravenous administration of prostaglandin E1 (0.05–

0.20 mg/kg/min), a potent and specific relaxant of ductal smooth muscle, causes

dilatation of the ductus arteriosus and usually provides adequate pulmonary blood

flow until a surgical procedure can be performed. This agent should be

administered intravenously as soon as cyanotic congenital heart disease is

clinically suspected and continued through the preoperative period and during

cardiac catheterization. Postoperatively, the infusion may be continued briefly as a

pulmonary vasodilator to augment flow through a palliative shunt or through a

surgical valvulotomy.4

Infants with less severe right ventricular outflow tract obstruction who are stable

and awaiting surgical intervention require careful observation. Prevention or

prompt treatment of dehydration is important to avoid hemoconcentration and

possible thrombotic episodes. Paroxysmal dyspneic attacks in infancy or early

childhood may be precipitated by a relative iron deficiency; iron therapy may

decrease their frequency and also improve exercise tolerance and general well-

being. Red blood cell indices should be maintained in the normocytic range. Oral

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propranolol (0.5–1mg/kg every 6 hr) may decrease the frequency and severity of

hypercyanotic spells, but with the excellent surgery available, surgical treatment is

indicated as soon as spells begin.4

Infants with symptoms and severe cyanosis in the 1st month of life have marked

obstruction of the right ventricular outflow tract or pulmonary atresia. Two

options are available in these infants: the first is a palliative systemic-to–

pulmonary artery shunt performed to augment pulmonary artery blood flow. The

rationale for this surgery, previously the only option for these patients, is to

decrease the amount of hypoxia and improve linear growth, as well as augment

growth of the branch pulmonary arteries. The second option is corrective open

heart surgery performed in early infancy and even in the newborn period in

critically ill infants. This approach has gained more widespread acceptance as

excellent short- and intermediate-term results have been reported. The advantages

of corrective surgery in early infancy vs a palliative shunt and correction in later

infancy are still being debated. In infants with less severe cyanosis who can be

maintained with good growth and absence of hypercyanotic spells, primary repair

is performed electively at between 4 and 12 month of age.4

Surgical

Palliative Shunt Procedures

Shunt procedures are performed to increase pulmonary blood flow. Indications for

shunt procedures vary from institution to institution. Many institutions, however,

prefer primary repair without a shunt operation regardless of the patient's age.

Selected indications for shunt procedures follow:

1. Neonates with ToF and pulmonary atresia.

2. Infants with hypoplastic pulmonary annulus, which requires a transannular

patch for complete repair.

3. Children with hypoplastic PAs.

4. Severely cyanotic infants younger than 3 months of age.

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5. Infants younger than 3 to 4 months old who have medically unmanageable

hypoxic spells.2

Although other procedures were performed in the past only Blalock-Taussig and

Gore-Tex interposition shunt (i.e., modified Blalock-Taussig) procedures are

performed at this time. They have a surgical mortality rate of 1% or less.

1. Classic Blalock-Taussig shunt, anastomosed between the subclavian artery

and the ipsilateral PA, is usually performed for infants older than 3

months. A right-sided shunt is performed in patients with left aortic arch; a

left-sided shunt is performed for right aortic arch.

2. Gore-Tex interposition shunt, placed between the subclavian artery and the

ipsilateral PA, is the procedure of choice for small infants younger than 3

months of age and sometimes for older infants. A left-sided shunt is

preferred for patients with left aortic arch, whereas a right-sided shunt is

preferred for patients with a right aortic arch.

3. The Waterston shunt, anastomosed between the ascending aorta and the

right PA, is no longer performed because of a high incidence of surgical

complications. Complications resulting from this procedure included too

large a shunt leading to CHF and/or pulmonary hypertension, and

narrowing and kinking of the right PA at the site of the anastomosis. The

latter created difficult problems in closing the shunt and reconstructing the

right PA at the time of corrective surgery.

4. The Potts operation, anastomosed between the descending aorta and the

left PA, is no longer performed either. It may result in heart failure or

pulmonary hypertension, as in the Waterston operation. A separate

incision (i.e., left thoracotomy) is required to close the shunt during

corrective surgery, which is performed through a midsternal incision.2

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Conventional Repair Surgery

Timing of this operation varies from institution to institution, but early surgery is

generally preferred.

Indications and Timing:

1. Symptomatic infants who have favorable anatomy of the right ventricular

outflow tract and PAs may have primary repair at any time after 3 to 4

months of age. Some centers perform primary repair in younger infants

and newborns, with an early mortality rate of <5%. Advantages cited for

early primary repair include diminution of hypertrophy and fibrosis of the

RV, normal growth of the PAs and alveolar units, and reduced incidence

of postoperative ventricular ectopic beats and sudden death.

2. Asymptomatic and minimally cyanotic children may have the repair

between 3 and 24 months of age, depending on the degree of annular and

PA hypoplasia.

3. Mildly cyanotic infants who have had previous shunt surgery may have

total repair 1 to 2 years after the shunt operation.

4. Asymptomatic and acyanotic children (i.e., “pink tet”) have the operation

at 1 to 2 years of age.

5. Asymptomatic children with coronary artery anomalies may have the

repair at 3 to 4 years of age, because a conduit placement may be required

between the RV and the PA.2

Total repair of the defect is carried out under cardiopulmonary bypass and

circulatory arrest. The procedure includes patch closure of the VSD and widening

of the right ventricular outflow tract by resection of the infundibular tissue and

placement of a fabric patch.2

For patients with uncomplicated ToF, the mortality rate is 2% to 3% during the

first 2 years. Patients at risk are those younger than 3 months and older than 4

15

years, as well as those with severe hypoplasia of the pulmonary annulus and

trunk. Other risk factors include multiple VSDs, large aortopulmonary collateral

arteries, and Down syndrome.2

Complications:

1. Bleeding problems may occur during the postoperative period, especially

in older polycythemic patients.

2. Pulmonary valve regurgitation may occur, but it is well tolerated.

3. CHF, although usually transient, may require anticongestive measures.

4. Right bundle branch block (RBBB) on the ECG caused by right

ventriculotomy, which occurs in over 90% of patients, is well tolerated.

5. Complete heart block (i.e., <1%) and ventricular arrhythmia are both rare.2

Rastelli Operation

Patients with severe hypoplasia or atresia of the right ventricular outflow tract and

those with coronary artery anomalies may have the procedure performed at about

5 years of age, at which time adult-sized homograft-valved conduits can be used.

The mortality rate for this procedure is 10% or less.2

Postoperative Follow-up

1. Long-term follow-up with office examinations every 6 to 12 months is

recommended, especially for patients with residual VSD shunt, residual

obstruction of the right ventricular outflow tract, residual PA obstruction,

arrhythmias, or conduction disturbances.

2. Some children develop late arrhythmias, particularly ventricular

tachycardia, which may result in sudden death. Arrhythmias are primarily

related to persistent RVH as a result of unsatisfactory repair. Complaints

of dizziness, syncope, or palpitation may suggest arrhythmias. A 24-hour

Holter monitor or exercise test may be needed.

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3. Varying levels of activity limitation may be necessary.

4. For patients who have had ToF repair, SBE prophylaxis should be

observed throughout life.

5. Children with sinus node dysfunction may require pacemaker therapy.

6. Pacemaker follow-up care is required for patients with implanted

pacemakers secondary to surgically induced complete heart block or sinus

node dysfunction.2

CASE

LEP, a 6 year old girl, was admitted to Pediatric Department of HAM Hospital on

January 29th 2010 with the main complaint: shortness of breath. This has been

experienced by the patient for the past day. Shortness of breath during activity is

found. Fever was found for the past 2 days. Fever declines by administrating fever

reliever. Seizures were not confirmed. Bluish baby was found since the age of 1

year. A decrease in appetite was found for the past two days. Easily exhausted

was found since the age 1 year. If exhausted the patient assumes a squatting

position. Defecation and urinate were normal. The patient is a former pediatric

cardiology patient and was previously advised to undergo surgery.

Physical examination

Consciousness was alert, body weight 10 kg, body length 85 cm, body

temperature 38,3 oC. Body weight/ Body length: 100%

General disease were severe and nutritional condition were good

There were no pale, icterus, and edema but dyspnea and cyanosis (+)

Head : Eye : Light reflexes (+/+), isochoric pupil

Sup. Palpebral edema (+/+), Inf. Conj. Palpebral pale (-/-)

Ears: Normal

Nose: Nose stril respiration (+)

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Mouth: Cyanosis (+)

Neck : Lymph node enlargement (-), JVP R-2 cm H2O

Chest : Left anterior hemithorax bulge

HR : 100 bpm, reg, murmur (+)

RR : 44 tpm, reg, rales (-)

Abdominal : Soepel

Hepar and lien: were not palpable

Peristaltis was normal

Extremities : Pulse was 100 tpm, reg, normal tone and volume

Clubbing finger (+), cyanosis (+)

Working diagnosis: Cyanosis CHD ec. ToF

Treatment:

- O2 1,5 L/i nasal cannule

- Assume knee chest position if spells occur

- IVFD RL 100 gtt/i micro (1 hour)

After which, maintenance IVFD Dextrose 5% NaCl 0,45% 40 gtt/i micro

- Propanolol 3 x 10 mg

- Bicarbonate 1 mEq/KgBW → 10 mEq in 50cc Dextrose 5% 120 gtt/i

micro (30 minutes)

Planning:

- Complete blood count

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- Arterial blood gas analysis & electrolyte

FOLLOW-UP

January 29th - January 31th 2010

S : Shortness of breath (+)

O: Consciousness was alert, T: 36,9 oC, BW 10 kg


Sup. Palpebral edema (+/+), Inf. Conj. Palpebral pale (-/-)

Ears: Normal

Nose: Nose stril respiration (+)

Mouth: Cyanosis (+)





Abdominal : Soepel






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Treatment:



- IVFD Dextrose 5% NaCl 0,45% 40 gtt/i micro

- Cefotaxim injection 500 mg/12 hours IV (day 1, 2, 3)


- Diet 1000 kkal + 20 gr protein

Laboratory findings on January 29th 2010

Complete blood count:

- Leucocytes : 6,62 K/uL

- Erythrocytes : 9,34 M/uL

- Hb : 14,5 g/dl

- Hct : 50,1 %

- Plt : 191 fl

- Blood glucose level : 246 mg/dl

- Na/K/Cl : 132/4,3/100

Arterial blood gas analysis:

- pH : 7,12

- pCO2 : 32,7

- PO2 : 24,4

- Bicarbonate : 12,4

- CO2 total : 13,4

- Base exes : -14,4

20

February 1st - February 4th 2010

S : Shortness of breath (-)



Inf. Conj. Palpebral pale (-/-)

Ears: Normal

Nose: Nose stril respiration (-)

Mouth: Cyanosis (+)





Abdominal : Soepel






21

Treatment:




- Cefotaxim injection 500 mg/12 hours IV (day 4, 5, 6, 7 → stop)



February 5th - February 8th 2010

S : Shortness of breath (-)



Inf. Conj. Palpebral pale (-/-)

Ears: Normal

Nose: Nose stril respiration (-)

Mouth: Cyanosis (+)





Abdominal : Soepel


22





Treatment:






Planning: Consult to Department of Cardio Thoracic Surgery (February 5th 2010)

Laboratory findings on February 5th 2010

Complete blood count:

- Leucocytes : 6,62 K/uL

- Erythrocytes : 9,85 M/uL

- Hb : 14,6 g/dl

- Hct : 52,7 %

- Plt : 231 fl

- LED : 17 mm/jam

- Na/K/Cl : 138/4,1/109

Kidney Profile:

- Ureum : 8,7 mg/dl

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- Creatinin : 0,17 mg/dl

- Uric acid : 5,3 mg/dl

Liver Profile:

- SGOT : 38,3 U/L

- SGPT : 8,1 U/L

- Total billirubin: 0,869 mg/dl

- Direct bilirubin: 0,295 mg/dl

Hepar Profile:

- Alkaline phosphatase: 117 U/L

The patient is a candidate for total correction based on the Cardio Thoracic

Surgery conference results.

The patient was discharged on February 8th 2010.

Patient was given Propanolol tablets 3 x 10 mg.

DISCUSSION

ToF patients can present with severe cyanosis or can be asymptomatic without

clinically evident cyanosis. The skin, lips, and mucous membranes inside the

mouth and nose take on a noticeably dusky blue color. The child usually tires

easily and begins panting with any form of exertion. The child may play for only a

short time before sitting or lying down. Once able to walk, the child often assumes

a squatting position to catch his or her breath and then resumes physical activity.

Squatting increases the pressure transiently in the aorta and left ventricle, causing

less blood to move into the left ventricle, more out the pulmonary artery to the

lungs. Episodes of extreme blue coloring occur in many children, usually in the

first 2-3 years of life. The child suddenly becomes blue, has difficulty breathing,

and may become extremely irritable or even faint. The spells often happen during

feeding, crying, straining, or on awakening in the morning. In this case, patient

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was a 6 years old girl with the main complaint was dyspnea. Dyspnea occurs on

exertion. Characteristically, If exhausted the patient assumes a squatting position.

It was found since the age 1 year. Hypoxic spells occur in the patient since the age

of 1 year. These spells usually occur in the morning after crying, feeding, or

defecation. The spells may last from a few minutes to a few hours.2, 4

Diagnosis is suggested by history and physical examination. The pulse is usually

normal, as is venous and arterial pressure. Clubbing finger are present and the left

anterior hemithorax may bulge anteriorly because of right ventricular

hypertrophy. The heart is generally normal in size. The systolic murmur is usually

loud and harsh; it may be transmitted widely, especially to the lungs, but is most

intense at the left sternal border. All of the sign was found from the physical

examination of the patient. The Diagnosis may also supported by chest x-ray

images and ECG, and established by 2-dimensional echocardiography with color

flow and Doppler studies. Chest x-rays show a boot-shaped heart with a concave

main pulmonary artery segment and diminished pulmonary vascular markings and

the ECG shows right ventricular hypertrophy and may also show right atrial

hypertrophy. Cardiac catheterization is often indicated before surgery to detect

concomitant abnormalities that may complicate surgical repair.4

Therapy is aimed at providing an immediate increase in pulmonary blood flow to

prevent the sequelae of severe hypoxia. The patient should be transported to a

medical center adequately equipped to evaluate and treat. Patients with less severe

right ventricular outflow tract obstruction who are stable and awaiting surgical

intervention require careful observation. Prevention or prompt treatment of

dehydration is important to avoid hemoconcentration and possible thrombotic

episodes. Paroxysmal dyspneic attacks in infancy or early childhood may be

precipitated by a relative iron deficiency; iron therapy may decrease their

frequency and also improve exercise tolerance and general well-being. Red blood

cell indices should be maintained in the normocytic range. Treatment of hypoxic

spells consists of oxygen administration and oral propranolol (0.5–1 mg/kg every

6 hour) may decrease the frequency and severity of hypercyanotic spells. Placing

the child in the knee-chest position (to increase venous return), and giving

25

morphine sulfate (to relax the pulmonary infundibulum and for sedation). If

necessary, the systemic vascular resistance can be increased acutely through the

administration of an α-adrenergic agonist (phenylephrine). If spells are frequent,

β-adrenergic antagonists (propranolol) decrease muscular spasm.3

Surgery to repair the defects of ToF involves:

Closing the ventricular septal defect (VSD) – the hole in the inner wall of

the heart between the lower chambers. A patch is used to cover the hole.

This cover stops the mixing of blood between the chambers. The oxygen-

rich blood now flows out of the heart only to the body, and the oxygen-

poor blood goes to the lungs.

Opening and enlarging the area that blood flows through as it leaves the

lower right side of the heart. The thickened heart muscle is opened, or a

small amount of heart muscle is removed. This improves the flow of

oxygen-poor blood to the lungs so that it can pick up more oxygen.

Opening or widening the pulmonary valve (between the right ventricle and

the pulmonary artery). The valve can be opened using a special

instrument, but often a patch is sewn on the heart to make the narrow area

bigger. This increases blood flow out of the heart to the lungs.5

Some patients are too weak to have open-heart, corrective surgery. They have

temporary surgery, which does not repair the defects of ToF, but partially

improves oxygen levels in the blood to give the baby time to grow and get

stronger so the problem can be fixed later. Instead of open-heart surgery, a

small opening can be made between the ribs.

The procedure involves:

Placing a tube (called a shunt) between a large artery branching off the

aorta and the pulmonary artery.

One end of the shunt is sewn to the pulmonary artery, and the other end is

sewn to an artery branching off the aorta. This creates an additional

pathway for blood to travel to the lungs.

26

This new pathway allows some of the blood in the aorta to flow through

the tube into the pulmonary artery, where it travels to the lungs to pick up

oxygen.

The shunt is removed when heart defects are repaired during the corrective

surgery.5

Treatments for this patient consists of oxygen administration, oral propranolol 3 x

10 mg and placing the child in the knee-chest position. The patient is a candidate

for total correction based on the Cardio Thoracic Surgery conference results. Most

cases can be corrected with surgery. Child that have surgery usually do well.

Without surgery, death usually occurs when the person reaches age 20.6

27

References

1. Medscape. Shabir Bhimji, MD, PhD. Tetralogy of Fallot. 2008 May 1 (last

updated). Available from: http://emedicine.medscape.com/article/163628-

overview

2. Myung K. Park MD, FAAP, FACC. Pediatric Cardiology for Practitioners.

4th ed. Missouri. Mosby; 2002

3. Kliegman RM, Marcdante KJ, Jenson HB, Behrman RE. Nelson Essentials

of Pediatrics. 5th ed. Pennsylvania. Saunders; 2007

4. Kliegman RM, Jenson HB, Behrman RE. Nelson Textbook of Pediatrics.

17th ed. Pennsylvania. Saunders; 2004

5. Medscape. Vibhuti N Singh. Tetralogy of Fallot: Surgical Perspective. 2008

Nov 11 (last updated). Available from:


6. Medscape. Vibhuti N Singh. Tetralogy of Fallot: Surgical Perspective.

20008 Nov 13 (last updated). Available from:


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Tetralogy of Fallot